JPS638045A - Installation structure of molding - Google Patents

Abstract

PURPOSE:To ensure strong adhesion to a molding by using adhesive wherein polymer or copolymer selected from groups consisting of acrylic acid, methacrylic acid, stylene, and acrylonitrile is mixed with acrylic adhesive including active hydrogen at a predetermined rate. CONSTITUTION:A molding 2 is installe on a adherend 1 made of a steel sheet via a pressure sensitive adhesive double coated tape 6. Adhesive 3 coated on said pressure sensitive adhesive double coated tape 6 is mixture wherein acrylic acid, one kind of polymer or copolymer of more than two kinds selected from groups which consist of acrylic acid, methacrylic acid or its derivative, stylene, and acrylonitrile by weight of 5-400 is mixed with acrylic adhesive including hydrogen by weight of 100. Owing to this constitution, adhesion to the adherend 1 is improved beyond stressed due to expansion/contraction of the molding 2, thereby enabling separation to be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION Object of the Invention (Field of Industrial Application) The present invention relates to a mounting structure for a molding mounted on the body, bumper, etc. of an automobile.

(Prior art) Automobile bodies and bumpers are made of synthetic resin or synthetic rubber, especially vinyl chloride resin or E.
A molding made of polyolefin vulcanized rubber such as PDM (ethylene-propylene-diene ternary copolymer rubber) and EPM (ethylene-propylene copolymer rubber) is attached.

A molding that is attached to the side of the body and has the function of preventing scratches caused by contact with other objects when opening a door, etc., as well as decoration, is called a side protection molding. is attached to the body using double-sided tape.

Therefore, the molding mounting structure described above has the advantage that the mounting work is easy, and since there is no need to make holes in the body, there is also the advantage that rust does not occur.

Further, the above-mentioned double-sided tape uses a base material such as a sponge made of a material such as acrylic rubber, polyethylene, or chloroprene rubber formed into a thin plate, or a nonwoven fabric, film, or paper.

Further, as the adhesive, an acrylic adhesive such as butylene acrylate, butyl methacrylate, 2-ethylhexyl acrylate, or a chloroprene adhesive is generally used.

(Problems to be Solved by the Invention) However, problems with the mold made of vinyl chloride resin include repeated contraction and expansion due to temperature differences between day and night, summer and winter, and low molecular weight molecules in the mold. Double-sided tapes are affected by various factors such as shrinkage due to volatilization of compounds, and shrinkage due to plasticizers and stabilizers in the molding decomposing and becoming low molecular due to interaction with heat, light, moisture, etc., and shrinkage due to these volatilizing in the air. It has been pointed out that peeling is likely to occur between the tape and the molding or between the double-sided tape and the body. In addition, a problem with molds made of EPDM, EPM, etc. is that these polyolefin vulcanized rubbers do not contain polar groups in the main chain of their molecules, so they cannot be coated with paint, adhesives, adhesives, etc. on the surface. It has been pointed out that even when applied, the adhesion of the resulting coating film is insufficient, and peeling is likely to occur between the double-sided tape and the molding or between the double-sided tape and the body.

As a result of repeated research into the mounting structure of moldings for the purpose of solving the above problems, the inventors have found that the above-mentioned vinyl chloride resin and E
We discovered an adhesive with strong adhesion to molds made of polyolefin vulcanized rubber such as PDMSEPM.
This has led to the present invention.

Structure of the Invention (Means for Solving Problems) The present invention provides a structure in which a molding is attached to an adherend using an adhesive, in which the adhesive is (al) based on 100 parts by weight of the active hydrogen-containing acrylic adhesive. , (bl) One type of polymer selected from the group consisting of acrylic acid, methacrylic acid or derivatives thereof, styrene, and acrylonitrile, or a mixture of two or more types of copolymers at a ratio of 5 to 400 parts by weight. It adopts the characteristic molding mounting structure.

(Function) With the above means, the adhesion of the molding to the adherend is significantly improved compared to the stress caused by the expansion and contraction of the molding caused by the various factors mentioned above, thereby preventing the molding from peeling off from the adherend.

(Example) Hereinafter, the composition of the adhesive used in the molding mounting structure of the present invention will be explained.

The active hydrogen-containing acrylic adhesive is obtained by polymerizing acrylic acid, methacrylic acid, or a mixture of two or more of these derivatives and the following active hydrogen compound in an organic solvent.

Specifically, the above acrylic acid derivatives include methyl acrylate, ethyl acrylate, n-butyl acrylate, 1
Examples include so-butyl acrylate, 2-9ethylhexyl acrylate, isodecyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, glycidyl acrylate, and dimethylaminoethyl acrylate.

In addition, methacrylic acid derivatives include methyl methacrylate, ethyl methacrylate, n-butyl methacrylate,
Examples include 1so-butyl methacrylate, 2-ethylhexyl methacrylate, isodecyl methacrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, glycidyl methacrylate, and dimethylaminoethyl methacrylate.

Furthermore, active hydrogen compounds include the above-mentioned acrylic acid, methacrylic acid, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, etc., as well as maleic acid, maleic anhydride, and fumaric acid. ,
Examples include organic acids such as citraconic acid, citraconic anhydride, itaconic acid, and itaconic anhydride.

A specific example of the active hydrogen-containing acrylic pressure-sensitive adhesive having the above composition will be shown below.

Acrylic adhesive-A: A mixed solvent consisting of toluene/cyclohexane/ethyl acetate = 1/1/1 (weight ratio) was added to a copolymer of n-butyl acrylate and maleic anhydride (acid value = 20 to 25). (37% solids).

Acrylic adhesive - B = Copolymer of n-butyl acrylate and fumaric acid (H&
A mixed solvent consisting of toluene/cyclohexane/ethyl acetate-1/1/1 (weight ratio) was added to (solid content 37%).

Acrylic adhesive-C: Copolymer of n-butyl acrylate and 2-hydroxyethyl methacrylate (hydroxyl value = 54 to 58) toluene/cyclohexane/ethyl acetate = 1/1/1 (
A mixed solvent consisting of (weight ratio) was added (solid content 37%).

Acrylic adhesive-D: Copolymer of n-butyl acrylate and 2-hydroxypropyl methacrylate (hydroxyl value = 26 to 30) toluene/cyclohexane/ethyl acetate = 1/1/1 (
(solid content: 37%).

(b) A type of polymer selected from the group consisting of acrylic acid, methacrylic acid or their derivatives, styrene, and acrylonitrile, or a copolymer of two or more types, in which each monomer is combined with a radical polymerization initiator in an organic solvent. Among them, radical polymerization was carried out according to a conventional method.

The radical polymerization initiators used include peroxides such as benzoyl peroxide (BPO), cumene hydroperoxide, t-butyl hydroperoxide, potassium persulfate, and ammonium persulfate, and abrasives such as azobisisobutyronitrile. Compounds can be exemplified.

Specific examples of the above polymers (or copolymers) are shown below. (
(Hereinafter, all parts mean parts by weight) Polymer-A: 20 parts of styrene and benzoyl peroxide (BPO)
0.05 part of the polymer in 80 parts of toluene for 8 hours at a temperature of 80° C. to obtain a polymer.

Polymer-B: A polymer was obtained by reacting 20 parts of methyl methacrylate with 05 parts of BPOo in 80 parts of toluene for 8 hours at a temperature of 80°C.

Polymer-C: A polymer was obtained by reacting 20 parts of ethyl acrylate with 05 parts of BPOo in 80 parts of toluene for 8 hours at a temperature of 80°C.

Polymer-D: 10 parts of methyl methacrylate, 10 parts of acrylonitrile, and 05 parts of BPOo were mixed in 80 parts of toluene for 8 hours.
A polymer was obtained by reacting at a temperature of 0°C.

Polymer-E: 16 parts ethyl acrylate and 4 parts propyl methacrylate
and BPOo, 05 parts in 80 parts of toluene for 8 hours,
A polymer was obtained by reacting at a temperature of 80°C.

Polymer-F = 35 parts of styrene, 35 parts of methyl methacrylate, 30 parts of glycidyl methacrylate, and 25 parts of BPO were reacted in 400 parts of toluene for 8 hours at a temperature of 80°C to obtain a polymer.

Polymer-G: A polymer was obtained by reacting 16 parts of ethyl methacrylate, 4 parts of glycidyl methacrylate, and 05 parts of BPOo in 80 parts of toluene for 8 hours at a temperature of 80°C.

Polymer-H: 19 parts methyl methacrylate, 1 part acrylic acid, and BPO
0.05 parts in 80 parts of toluene for 8 hours at a temperature of 80° C. to obtain a polymer.

Next, to produce the adhesive, simply mix 5 to 400 parts by weight of the polymer (A-H) to 100 parts by weight of the active hydrogen-containing acrylic adhesive (A-D) in an organic solvent. However, if the amount of the polymer (A-H) is less than 5 parts by weight or more than 400 parts by weight, the adhesive strength decreases.

Organic solvents used during mixing include saturated hydrocarbons such as n-hexane and cyclohexane; aromatic hydrocarbons such as benzene, toluene, and xylene; ethers such as dioxane and tetrahydrofuran; acetic acid such as ethyl acetate and propyl acetate. Ester: A solvent formed by one type of solvent or a mixture of two or more types appropriately selected from ketones such as acetone, cyclohexanone, and methyl ethyl ketone.

Next, specific examples of the adhesive used in the present invention are shown in Table 1 below.
Shown in ~8.

Table-1 (Adhesive-1) Table-2 (Adhesive-2) Table-3 (Adhesive-3) Table-4 (Adhesive-4) Table-5 (Adhesive-5) Table-6 (Adhesive-5) Adhesive-6) Table-7 (Adhesive-7) Table-8 (Adhesive-8) Next, an example of a molding mounting structure using the above-mentioned adhesives-1 to 8 will be explained using drawings. .

In this embodiment, as shown in FIG. 1, a molding 2 manufactured by extrusion molding of vinyl chloride resin is attached to an automobile body, that is, an adherend l made of a steel plate coated with acrylic, via a double-sided tape 6. installed.

The double-sided tape 6 is made up of a base material 5 made of a 5x polyethylene foam, and an adhesive 3 and an adhesive 4 coated on both sides of the base material 5. The adhesive 4 coated on the side of the molding 2 is a conventionally known chloroform Blend rubber adhesive (manufactured by Konishi Co., Ltd., r
G-17J), and the adhesive 3 coated on the adherend 1 side is the adhesive 1 described above. The mold 2 used was made by extrusion molding a vinyl chloride resin having a composition shown in Table 9 below at 170°C.

Table 9 In the above example, a well-known chloroprene adhesive was used on the molding side of the base material, but the mounting structure of the molding of the present invention is not limited to the above example, and instead of the chloroprene adhesive. , a structure using a well-known urethane adhesive, an acrylic adhesive, or any one of the adhesives 1 to 8 described above may be adopted.

Further, instead of the foamed polyethylene, foamed acrylic rubber, foamed urethane, foamed chloroprene rubber, nonwoven fabric, film, paper, etc. can also be used as the base material of the double-sided tape.

Next, in order to measure the adhesive strength of the adhesives-1 to 8, a test was conducted using the following method.

Test method: Two molds made of vinyl chloride resin using the above example were prepared, adhesive-1 was applied to the back surfaces of the molds, and the molds were air-dried at room temperature for 30 minutes.

Thereafter, the adhesive-coated surfaces of these moldings were placed on top of each other and left at room temperature for 3 days, after which a shear test was conducted at a tensile rate of 30 mm/min.

In addition, Table 1 below is used as adhesives-2 to 8 and comparative examples.
Similar tests were conducted using adhesives with compositions shown in O111 (Comparative Examples-1 and 2) and commercially available acrylic adhesives (manufactured by Mitsubishi Rayon Co., Ltd., "Dyanal-882" Comparative Example-3). The results shown in -12 were obtained.

Table 10 (Comparative Example 1) Table 11 (Comparative Example 2) Furthermore, these moldings were left in a constant temperature bath at 80°C for 5 hours to thermally deteriorate, and then the shear strength was measured. The results shown in -13 were obtained.

Table 12 Table 13 From the above test results, it was found that the shear strength of Adhesives 1 to 8 was sufficient for use in a structure in which a molding made of vinyl chloride resin is attached to an automobile body. In addition,
Comparative Example-1 is polymer-F for acrylic adhesive-A.
Because the ratio of polymer-F to acrylic adhesive-A was small, and because the ratio of polymer-F to acrylic adhesive-A was excessive in comparative example-2, sufficient shear strength could not be obtained.

Next, separate attachment structures for moldings using the above-mentioned adhesives-1 to 8 will be explained with reference to the drawings.

In this embodiment, as shown in FIG. 2, a molding 2 manufactured by extrusion molding EPDM is attached to an automobile body, that is, a steel plate coated with acrylic paint, through an adhesive 3 coated on the back surface of the molding 2. It is attached to the body 1.

The molding 2 was manufactured by extruding EPDM having the composition shown in Table 14 and then vulcanizing it at 200°C for 5 minutes.

Next, in order to measure the adhesive strength of the adhesives-1 to 8, a test was conducted using the following method.

Test method: Two molds made of EPDM used in the above examples were prepared, adhesive-1 was applied to the back surfaces of the molds, and the molds were air-dried at room temperature for 30 minutes.

Thereafter, the adhesive-coated surfaces of these moldings were stacked together and left at room temperature for 3 days, after which a shear test was conducted at a tensile speed of 30 m/min.

In addition, adhesives-2 to 8 and the comparative example-
A similar test was conducted using I, 2 and a commercially available chloroprene rubber adhesive (manufactured by Konishi Co., Ltd., rG-17J, Comparative Example 4), and the results shown in Table 15 were obtained.

Furthermore, these moldings were left in a constant temperature bath at 80° C. for 5 hours to thermally deteriorate, and then the shear strength was measured, and the results shown in Table 16 were obtained.

Table-15 Table-16 From the above test results, the shear strength of Adhesives-1 to 8 is E
It was found that the molding made of PDM has sufficient strength when used in a structure for attaching it to an automobile body.

Since the adhesive used in the present invention has strong adhesion, it is not limited to the mounting structure of the molding described above, and can generally be applied to structures for attaching various synthetic resin materials to metals or other adherends. You can also.

Effects of the Invention As detailed above, the present invention exhibits the effect of significantly improving the adhesion between the body and the molding when it is used when attaching a molding made of vinyl chloride resin, EPDM, etc. to an automobile body. This is an excellent invention as a molding mounting structure.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing an embodiment of the structure in which an automobile body is used as an adherend and a molding is attached to this, and FIG. 2 is a cross-sectional view showing a separate structure. 1. Adherent, 2. Molding, 3. Adhesive.

Claims (1)

[Claims] 1. In a structure in which a molding is attached to an adherend using an adhesive, the adhesive contains (a) 100 parts by weight of an active hydrogen-containing acrylic adhesive, (b) acrylic acid, methacrylic acid, etc. A molding mounting structure characterized in that it is a polymer selected from the group consisting of acids or derivatives thereof, styrene, and acrylonitrile, or a mixture of two or more copolymers in a ratio of 5 to 400 parts by weight. . 2. The molding mounting structure according to claim 1, wherein the molding is attached to an adherend via a tape coated with an adhesive.